Title: ipchains setup bare bones
Subject: Quick and dirty ipchains

Identify the version on your system.
  # /sbin/ipchains --version
  ipchains 1.3.9, 17-Mar-1999

Check out: http://www.linuxdoc.org/HOWTO/IPCHAINS-HOWTO-4.html

See what your system is currently doing.
  # /sbin/ipchains -M
  # /sbin/ipchains -L

Enable a rule (ip masquerading as an example), and then go to a web site:
  #/sbin/ipchains -A forward -s 10.1.0.0/24 -j MASQ

List of current masqueraded connections. 
  # /sbin/ipchains -M

List the rules int current lists rules.
  # /sbin/ipchains -L 
    Chain input (policy ACCEPT):
    Chain forward (policy DENY):
    target     prot opt     source                destination           ports
    MASQ       all  ------  10.1.0.0/24       anywhere              n/a
    Chain output (policy ACCEPT):
    root      1024  0.0  0.7  1240  500 pts/1    S    01:04   0:00 grep icq

  # cat my_firewall 
    :input ACCEPT
    :forward DENY
    :output ACCEPT
    -A forward -s 10.1.0.0/255.255.255.0 -d 0.0.0.0/0.0.0.0 -j MASQ

Add an entery so it starts when you boot.
  # vi /etc/rc.d/rc.firewall
    /sbin/ipchains -P forward DENY
    /sbin/ipchains -A forward -s 10.1.0.0/24 -j MASQ